So I finally got around to the
oil change that's been due since I got 707 - had to mount the
oil thermostat and then get the remote filter bracket powder coated, and I only wanted to remove the
oil filter etc. one time.
Went from some pretty old and black (2500 miles) Castrol 10W-50 to Castrol 5W-30, with a Wix filter. Eleven freakin' quarts!
Drove around for half an hour and noticed some interesting things. First, the oil temp started rising much earlier - there have been times I've warmed it and driven it for 15 minutes without a nudge in oil temp. It also continued to rise steadily, right past the 70* former high to 80* and then briefly to 80+. I actually got it warm enough to get some circulation through the cooler.
Oil pressure stayed good, perhaps 5 psi lower at cruise RPMs (55-60 instead of 60-65) even when hot. Idle pressure is actually higher, stable at 20 psi instead of dipping a little below 20 when hot.
I can't quite figure out how fresh, slightly thinner oil would heat so much faster and to 10-12 degrees higher than I could ever get the prior load. This was all street driving, BTW, not even any highway time.
Oh, and then I look under the hood and find I have a small fuel leak, right off the pump. Bleah. About one drip per second and it stops in a minute or two. Next on the list...